This application claims the priority of German application 196 47 464.7, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a vehicle seat, especially for single-track vehicles, for example motorcycles.
A vehicle seat for a motorcycle is known from U.S. Pat. No. 4,506,754. In this design, the seat, footrests, and possibly the handlebars of the motorcycle can be adjusted to the body size of the individual rider. The seat can be shifted lengthwise of the vehicle. In addition, it has a tiltable backrest that serves as an extra seat when folded down. The backrest can assume either an upright position in which it serves as a backrest, or the above mentioned folded-down position; no intermediate positions are expressly mentioned.
The previously known design allows adjustment within a broad range, but the individual adjustment mechanisms are designed in a relatively cumbersome fashion. With the large number of adjustment possibilities, moreover, there is the risk that the rider will not find his desired position or that it will take a long period of time to make the adjustments.
A goal of the invention is to design a vehicle seat that can be easily adjusted and will fit the different body sizes of riders, at least within acceptable limits, as well as being comfortable.
These and other goals have been achieved according to the present invention a vehicle seat for a single-track vehicle comprising: a seat; and a folding backrest operatively coupled to said seat via a rotary joint such that said backrest is pivotable from an upright position for use as a backrest into a lowered position for use as an extra seat, and such that said backrest is adjustable to a plurality of angles of inclination in said upright position.
These and other goals have also been achieved according to the present invention by providing a mounting structure for a vehicle seat of a single-track vehicle, comprising: a support part to be secured to the single-track vehicle; first and second bearings extending upwardly from rear support part, each of said bearings defining a respective mounting bore aligned on a first axis; a bearing section to be coupled to said vehicle seat, said bearing section being rotatably coupled to said first and second bearings via said respective mounting bores, said bearing section defining an adjusting bore extending therethrough essentially parallel to said first axis; an adjusting shaft extending through said adjusting bore, said adjusting shaft comprising a first portion engaged with said bearing section and rotatable about a second axis essentially parallel to said first axis, said adjusting shaft further comprising a pin extending axially from said adjusting bore and arranged eccentrically with respect to said second axis, said pin being selectively engageable with an elongate hole and a locking bore defined in said first bearing, said pin locking said bearing section in a lowered position when engaged with said locking bore, and said adjusting shaft being rotatable when said pin is engaged with said elongate hole to adjust an angle of inclination of said bearing section about said first axis of rotation.
It has been found that the rider tries to achieve a comfortable position on a vehicle by tilting his upper body more or less backward depending on his body size. This discovery is utilized by the invention in that, in contrast to the prior art, it makes only the backrest adjustable in terms of its tilt. Adjustability is not absolutely necessary for the other parts, namely the footrests and handlebars.
In a preferred embodiment of the invention, the adjustment mechanism has an adjusting shaft that is rotatably mounted in a portion of the backrest and engages a rear supporting part fastened to the body of the vehicle via an eccentric component. The rear supporting part simultaneously serves to pivotably mount the backrest.
When the adjusting shaft is turned, the eccentric component of the backrest forces the different inclinations to be assumed, while it is supported in a corresponding bore in the rear supporting part. In order to provide the operator with distinct adjustment positions, it is also advantageous to permit the tilt adjustment to be performed in fixed stages. This is accomplished by notched marks in which the adjusting shaft is secured by spring force.
In one advantageous embodiment of the invention, the adjusting shaft makes it possible, in addition to adjusting the tilt, to fold down the backrest as well. It then secures the backrest in the folded position. In this manner, all of the possible adjusting functions of the backrest are combined for the most part into one component.
It has also been found that under certain circumstances, a backrest that has been optimally adjusted tiltwise can be perceived as uncomfortable, especially on a long trip. In one advantageous embodiment of the invention therefore, the backrest is made flexible by spring action within preset limits at each of its tilted positions. This is accomplished in simple fashion by a leaf spring that connects the actual cushion of the backrest with its bearing or adjusting section.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.